The joy of the annual whale migration has been tempered by the discovery of two dead mammals on Coffs Coast beaches.

The pair of deceased humpback whales (Megaptera novaeangliae) were reported to the NSW National Parks and Wildlife Services (NPWS) within 24 hours over the weekend.

The first whale was a new-born male which washed on the beach north of Scotts Head on late Friday afternoon.

The second whale was a humpback that had been previously seen resting within metres of rocks at Bonville Headland last Wednesday.

It had been monitored throughout that day by staff from Dolphin Marine Magic, ORRCA Inc and the NPWS before it swam off into open water late Wednesday afternoon. This whale later washed up dead on Bonville Beach around midday on Saturday.

Staff from Dolphin Marine Magic (DMM) were dispatched to both sites to collect biological samples and measurement data from the animals.

DMM's Manager of Life Science Aaron Tolley said the calf had drifted back out to sea before staff arrived.

"Collecting biological samples and measurement data from stranded dead whales increases our knowledge and understanding of cetaceans in general, cetacean disease and other factors that may influence these stranding events," Aaron said.

"This information is critical to improving our ability to manage future stranding events and may even assist in finding ways to prevent whale strandings occurring.

"While it is great to see humpback whale populations increasing, the unfortunate side-effect is that it is likely that we will see an increase in whale stranding and entanglement events along the NSW coast.

"Accordingly Dolphin Marine Magic, ORRCA Inc and the NSW National Parks and Wildlife Service are always ready to assist in any marine mammal events as required."

If you see a whale or marine mammal in distress, call Dolphin Marine Magic on 1300 547 737, ORRCA Inc or NSW National Parks and Wildlife Services.